JP3057467B2 - Engine ignition control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ignition control device for an engine, and more particularly to a technique for switching an ignition timing in an engine in which a valve opening characteristic is switched according to an operating condition in response to the switching of the valve opening characteristic. .

[0002]

2. Description of the Related Art Conventionally, a lift characteristic (opening characteristic) of an intake valve or an exhaust valve has been changed, for example, by using a high-speed cam for the purpose of achieving both high torque characteristics during low-medium-speed operation and improvement in output during high-speed operation. It is known that the low-speed cam and the low-speed cam are used differently depending on the operating conditions, thereby controlling the intake / exhaust timing or the intake / exhaust amount (JP-A-63-167016, JP-A-63-163163). -5780
No. 5, JP-A-5-171909, etc.).

In an engine equipped with a system for switching valve opening characteristics as described above, since an appropriate ignition timing differs for each valve opening characteristic, an ignition timing map is individually set in advance for each valve opening characteristic. Switching of the ignition timing map according to switching of the valve opening characteristic (cam) has been performed.

[0004]

However, Japanese Unexamined Patent Application Publication Nos. 63-167016 and 63-5780 disclose the above-mentioned publications.
No. 5, Japanese Patent Application Laid-Open No. 5-171909, etc., in a system for switching valve opening characteristics by controlling operating hydraulic pressure, a switching command is output based on operating conditions (the hydraulic control valve is turned off). An operation delay time due to a change in oil pressure occurs before the valve opening characteristic is actually switched (after opening / closing is controlled).

For this reason, if the ignition timing is switched in synchronization with the switching command, the switching of the ignition timing is performed before the valve opening characteristic is actually switched, which adversely affects driving performance such as occurrence of switching shock. Become. Here, the operation delay time may be set in advance as a fixed constant, and the ignition timing may be switched when the predetermined operation delay time has elapsed from the switching command. Therefore, it is difficult to stably switch the ignition timing at the optimal timing (at the time when the valve opening characteristic is actually switched).

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems. In an engine in which the valve opening characteristics are controlled to be switched according to the operating conditions, the switching of the ignition timing corresponding to each valve opening characteristic is performed by changing the actual valve opening characteristics. It is an object of the present invention to accurately and synchronously perform switching of characteristics.

[0007]

An engine ignition control device according to the present invention is configured as shown in FIG. In FIG. 1, the valve opening characteristic switching means is means for switching the valve opening characteristic of the engine to a plurality of preset types, and a switching command output means is provided with a valve opening characteristic switching means for the valve opening characteristic switching means in accordance with operating conditions. Outputs the switching command of the open characteristics.

On the other hand, the valve opening characteristic switching timing detecting means detects the amount of engine intake air after the switching instruction output means outputs a valve opening characteristic switching command.
The valve opening characteristics are actually switched when the
It is detected as the timing that has come . Here, the switching time learning means, further the timing detected by the valve opening characteristic switching timing detection means, and the learning for each direction of the switched as the time from the output of the switching command
Remember new . In addition, the learning prohibiting means includes switching time learning.
Time from when the switching command is output in the means
Update learning is prohibited during transient operation of the engine
You. Then, the ignition timing switching means includes a switching time
Switch the time for each switching direction stored in the learning means
At the point in time after the start command, the ignition timing previously set for each valve opening characteristic is switched and set.

[0009]

According to a second aspect of the present invention, in the ignition control device for an engine, the valve opening characteristic switching means switches the valve opening characteristic by operating hydraulic pressure.
The switching time learning means learns the time from when the switching command is output according to the temperature of the hydraulic oil to when the valve opening characteristic is actually switched for each switching direction .

[0011]

In the ignition control device for an engine according to the first aspect of the invention, when the switching of the valve opening characteristic is controlled in accordance with the operating condition, the timing at which the valve opening characteristic is actually switched after the switching command is output. , Engine intake empty
It is detected as a point in time when a change in the air volume occurs . And
This detection result is learned and updated for each switching direction.
The ignition timing corresponding to the valve opening characteristic is switched at the time when the time learned and stored elapses from the switching command. As a result, even when the time from the switching command to the actual switching of the valve opening characteristic fluctuates, the switching of the ignition timing can be performed in synchronization with the actual switching of the valve opening characteristic. Also, engine overload
During transfer operation, the valve opening characteristics are actually switched from the switching command.
Learning to update the time until switching is prohibited.
Learning based on the issued switching timing is avoided.
You.

Further, in the device according to the second aspect of the present invention,
A time when a change in the engine intake air amount occurs after the switching command is detected as a timing at which the valve opening characteristic is actually switched. That is, in general, when the switching of the valve opening characteristic is performed, the charging efficiency changes, and this causes a change in the engine intake air amount. It is assumed that the change in the intake air amount is caused by the change in the charging efficiency due to the switching of the valve opening characteristic.

[0013]

Further, in the apparatus according to the second aspect of the present invention,
In the configuration in which the switching of the valve opening characteristic is performed by the operating oil pressure, the learning of the operation delay time is performed in accordance with the temperature of the operating oil, and the learning of the operation delay time is performed in response to the change in the operating delay time due to the fluctuation of the operating oil temperature. The switching of the ignition timing is performed .

[0015]

Embodiments of the present invention will be described below. FIG. 2 is a block diagram schematically showing the system configuration of the present embodiment.
In FIG. 2, an engine (not shown) is provided with a variable valve mechanism 101 (valve opening characteristic switching means) for selectively switching a valve opening characteristic (lift characteristic) to a plurality of preset types.

The variable valve mechanism 101 is a hydraulic variable mechanism that switches a valve opening characteristic by operating hydraulic pressure, and the supply of the operating hydraulic pressure is controlled by a switching valve 103 that is driven and controlled by a control unit 102 as switching instruction output means. (Hydraulic control valve). The control unit 102 having a built-in microcomputer includes a rotation speed sensor 104 for detecting the engine rotation speed Ne, an air flow meter 105 for detecting the intake air flow rate Qa of the engine, and the variable valve mechanism 10.
1 to input a detection signal from an oil temperature sensor 106 for detecting the temperature of the hydraulic oil, determine the valve opening characteristic based on the detection signal, and switch to the valve opening characteristic corresponding to the determination. A switching command (open / close control signal) is output to the switching valve 103.

Since the appropriate ignition timing changes according to the change in the charging efficiency due to the valve opening characteristic, the control unit 102 has an ignition timing map for each valve opening characteristic in advance, and switches the valve opening characteristic. The ignition timing map is switched and set accordingly (ignition timing switching means), the ignition timing is determined based on the selected ignition timing map, and an ignition signal is output to the ignition device 107.

Note that, as the ignition timing map, a map in which ignition advance values are stored for each operation region divided by the engine load and the engine rotation speed Ne is used. The ignition device 107 includes an ignition plug, an ignition coil, a power transistor, and the like. Here, FIG.
6 to 6 show specific examples of the variable valve mechanism 101. FIG.

Describing this, each cylinder is provided with a single rocker arm 1 corresponding to two intake valves V. The base end of the rocker arm 1 is swingably supported by a cylinder head via a hollow main rocker shaft 3 common to the cylinders, and the forked ends of the rocker arm 1 abut on the stem top of the intake valve V. . The rocker arm 1 is formed in a substantially bifurcated shape in plan view, and the rocker arm 1 is provided with a single free cam follower 2 substantially above the center thereof. In FIG. 4, rollers 11, 11 with which the low speed cams 21, 21 abut are provided on both sides of the free cam follower 2.

The base end of the free cam follower 2 is supported by the rocker arm 1 via a sub rocker shaft 16 so as to be swingable (relatively rotatable). The free cam follower 2 does not have a portion that comes into contact with the intake valve V, and a cam follower portion 2A that slides on the high-speed cam 22 is formed at the tip of the free cam follower 2 so as to protrude in an arc shape. Further, a recess 27 into which the spring retainer 29 is slidably fitted is provided below the free cam follower 2.
The spring retainer 29 is configured such that the base end thereof abuts on the rocker shaft 3 by the elastic biasing force of the coil spring 26 supported on the bottom surface of the recess 27.

Further, the free cam follower 2 has a stepped portion 2B with which a later-described lever member 7 is engaged, and an inclined portion 2C connected to the stepped portion 2B, below the cam follower portion 2A. A lever member 7 is provided below the rocker arm 1 so as to be swingable by a pin 6 on the side of the rocker shaft 3. A protrusion 7A is integrally formed on the upper side of the lever member 7, and the return spring 9 and the spring retainer 10 housed in the concave portion 8 formed in the rocker arm 1 engage with the free cam follower 2 described above. It is urged in the direction to be released.

On the other hand, an operating plunger 31 driven by supplying operating hydraulic pressure to a hydraulic chamber 34 provided in the rocker arm 1 abuts on the lower end of the lever member 7.
An oil passage for guiding operating oil pressure to the hydraulic chamber 34 is provided through the inside of the rocker arm 1 and the main rocker shaft 3. The rocker arm 1 is formed with a through hole 41 having one end opened to the hydraulic chamber 34 and the other end penetrating a bearing surface for the main rocker shaft 3. Further, an oil gallery 42 is formed in the main rocker shaft 3 in the axial direction, and the oil gallery 42 communicates with the through hole 41 of the rocker arm 1 through the through hole 43.

The oil gallery 42 is selectively guided with a discharge oil pressure of an oil pump (not shown) driven by an engine via a switching valve 103 whose operation is controlled by the control unit 102. Low speed cam 2
The high-speed cam 22 and the high-speed cam 22 therebetween are integrally formed on a common camshaft 20 to satisfy a valve lift characteristic (opening characteristic) required at low engine speed and high engine speed. Are formed in different shapes.
That is, the high-speed cam 22 has a cam profile that makes at least one of the valve lift amount and the valve open period larger than the low-speed cam 21. In the present embodiment, both the valve lift amount and the opening period are increased, and two types of valve opening characteristics can be switched by selectively using the high-speed cam 22 and the low-speed cam 21. I have.

According to the variable valve mechanism 101 having the above structure,
In a state where the operating oil pressure is not supplied to the hydraulic chamber 34 (a hydraulic relief state by the switching valve 103), the rocker arm 1 swings according to the cam profile of the low speed cam 21 to open and close each intake valve V. At this time, the free cam follower 2
Is swung by the high-speed cam 22, but the spring 9
The lever member 7 is at the position shown by the solid line in FIG. Therefore, even if there is an input from the free cam follower 2, the movement of the rocker arm 1 is not affected only by the bending of the spring 26.

On the other hand, when the operating oil pressure is supplied to the hydraulic chamber 34, the operating plunger 31 swings the lever member 7 against the return spring 9 to bring the lever member 7 to the position shown by the broken line in FIG. . In this state, the rocker arm 1 and the cam follower 2 are connected and integrated as a result of the end of the lever member 7 being engaged with the step 2B of the free cam follower 2 and swinging about the main rocker shaft 3. become.

Here, since the high-speed cam 22 is formed so that both the valve opening angle and the valve lift are larger than the low-speed cam 21, the free cam follower 2 is integrated with the rocker arm 1. When rocking, rocker arm 1
Roller 11 is lifted from the low speed cam 21, and each intake valve V is driven to open and close according to the profile of the high speed cam 22, and both the opening angle and the lift amount are increased.

On the other hand, when switching from the high-speed cam 22 to the low-speed cam 21, the hydraulic pressure guided to the hydraulic chamber 34 is reduced by controlling the switching valve 103, and the lever member 7 and the operating plunger are restored by the elastic restoring force of the return spring 9. 31 is moved to the original position (the position indicated by the solid line in FIG. 5), and the locker arm 1 is released. Thus, the switching valve
By selectively supplying the operating oil pressure to the hydraulic chamber 34 by the valve 103, the valve opening characteristic adapted to the low speed range according to the profile of the low speed cam 22 and the opening speed of the low speed cam 22 according to the profile of the high speed cam 21 are increased. Any one of the valve opening characteristics suitable for a high speed range where the angle and the lift amount are large can be switched and selected.

In this embodiment, the valve opening characteristic switching means is constituted by the rocker arm 1, free cam follower 2, lever member 7, plunger 31, hydraulic chamber 34, switching valve 103 and the like. In this embodiment, the switching between the high-speed cam 21 and the low-speed cam 22 is performed by whether or not the rocker arm 1 and the cam follower 2 are connected by swinging the lever member 7 as described above. However, the mechanism for switching the cam is not limited to the above.

For example, as disclosed in JP-A-63-167016 and JP-A-63-57805, a high-speed rocker arm and a low-speed rocker arm are fitted in a direction parallel to the rocker shaft. The configuration may be such that switching between the high-speed cam and the low-speed cam is performed by selectively connecting the hole and the plunger by engagement and disengagement.

Further, instead of using a plurality of cams, it is possible to mount a cam sprocket capable of controlling the cam phase with a constant operating angle on the camshaft, and switch the intake valve opening / closing timing to an appropriate timing for each speed range. Variable valve timing control device (“New vehicle manual (FGY32-
1), pages B-44 to B-45, edited and published by Nissan Motor Co., Ltd., issued in August 1991), and the configuration of the variable valve mechanism 101 is not limited.

Here, the switching control of the valve opening characteristics (between the high-speed cam and the low-speed cam) performed by the control unit 102 through the switching valve 103 and the setting control of the ignition timing accompanying the switching control are described. This will be described with reference to the flowchart of FIG. In this embodiment, the functions of the switching command output means, the valve opening characteristic switching timing detecting means, the ignition timing switching means, and the switching time learning means are performed by the control unit 102 as shown in the flowchart of FIG. In preparation.

In the flowchart of FIG. 7, first, in step 1 (S1 in the figure, the same applies hereinafter),
Referring to a map in which a reference intake air amount Qs (reference air amount) is stored in advance for each engine rotation speed Ne, a rotation speed sensor
A reference intake air amount Qs corresponding to the current engine speed Ne detected at 104 is obtained. The reference intake air amount Q
s is a low speed cam 21 and a high speed cam for each rotation speed Ne.
Engine intake air volume (torque) using any of 22
The absolute value of the intake air amount of the engine when is substantially equal to each other is obtained in advance, and this is set as the reference intake air amount Qs. Here, at the same rotational speed Ne, with the reference intake air amount Qs as a boundary, a higher torque can be obtained by using the high-speed cam 22 on the side with a larger air amount on the higher load side,
On the lower load side where the amount of air is smaller, higher torque can be obtained by using the low speed cam 21.

That is, switching between the high-speed cam 22 and the low-speed cam 21 is required to be performed under the condition that substantially the same torque is obtained before and after the cam switching. On the other hand, the engine output torque is correlated with the engine intake air amount (cylinder intake air amount), and the absolute value of the intake air amount under the condition that the engine intake air amount is the same for each cam differs depending on the engine rotation speed Ne. .

Therefore, the engine intake air amount (reference intake air amount Qs), which is a switching timing according to the engine rotation speed Ne, is set. Depending on whether the actual air amount Q is larger or smaller than the reference intake air amount Qs, In this case, it is determined which of the cams is in an operation range in which a higher output torque can be obtained. The switching of the cams is performed when the actual intake air amount Q crosses the reference intake air amount Qa. When the actual intake air amount Q becomes the reference intake air amount Qs, any one of the cams is used. Is also a condition under which the same amount of air (engine torque) can be obtained, so that a change in the amount of air due to cam switching can be suppressed, and generation of a torque step can be avoided.

Naturally, the throttle valve opening differs when the reference intake air amount Qs is obtained for each rotation speed Ne. In the next step 2, the air flow meter 10
5 and the engine speed N
Then, the engine intake air amount Q (cylinder intake air amount) obtained from e is read.

In step 3, the reference intake air amount Qs is compared with the actual engine intake air amount Q read in step 2. In the case where the actual engine intake air amount Q is in the operating range larger than the reference intake air amount Qs, higher torque is obtained by using the high-speed cam 22 in the present embodiment, and therefore, in step 3, When it is determined that the actual engine intake air amount Q exceeds the reference intake air amount Qs, the process proceeds to step 4, and a command to switch to the high-speed cam 22 is output.

The switching command is output as a switching (opening / closing) switching signal for the switching valve 103, and the switching to the high-speed cam 22 is performed by supplying the hydraulic pressure to the hydraulic chamber 34 as described above. Switching valve 10 on the side where
This is done by switching 3. On the other hand, in step 3,
The actual engine intake air amount Q is equal to the reference intake air amount Q.
When it is determined that the speed is equal to or less than s, in such an operation region, higher torque is obtained by using the low-speed cam 21 in the present embodiment. Output.

The switching command to the low-speed cam 21 is as follows:
This is a control signal for switching the switching valve 103 in the direction of decreasing the hydraulic pressure in the hydraulic chamber 34, whereby the engagement between the rocker arm 1 and the free cam follower 2 is released, and the low-speed cam 21 is switched. As described above, the switching between the high-speed cam 22 and the low-speed cam 21 (switching of the valve opening characteristic) is performed based on the comparison between the reference intake air amount Qs set according to the engine rotation speed Ne and the actual intake air amount Q. ), The engine intake air amount Q greatly changes when switching between the high-speed cam 22 and the low-speed cam 21.
Thus, generation of a large torque step can be avoided.

However, instead of the switching command based on the level determination of the engine intake air amount Q, a switching command may be issued according to the engine speed Ne.
The operating condition for determining the timing for outputting the switching designation is not limited to the engine intake air amount Q. By the way, the high-speed cam 22 and the low-speed cam 21
Even if the switching valve 103 is controlled to switch between the low-speed cam 21 and the high-speed cam 22 or from the high-speed cam 22 to the low-speed cam 21, the operating oil pressure change , A predetermined operation delay time is required.

Here, the operation delay time varies depending on the engine and varies depending on the temperature (viscosity) of the hydraulic oil. In this embodiment, the operation delay time is learned for each temperature of the hydraulic oil. After outputting the switching command to the high-speed cam 22 in step 4, the operation delay in the switching operation to the high-speed cam 22 at the current hydraulic oil temperature is referred to in step 5 by referring to the learning result. Time TD
1 is read.

In step 6, the elapsed time from the output of the command to switch from the low-speed cam 21 to the high-speed cam 22 is determined by the operation delay time T read in step 5.
It is determined whether or not D1 has been reached. Here, if the time elapsed since the switching command was issued has not reached the operation delay time TD1, the switching command to the high-speed cam 22 has been output, but actually, the intake valve is still operated by the low-speed cam 21. It is determined that V is being driven to open and close, and the routine proceeds to step 13, where the ignition timing is determined by referring to a preset ignition timing map (low-speed ignition timing map) adapted to the state in which the low-speed cam 21 is used. Determine and perform ignition control.

In the ignition control, data of a corresponding operation region of an ignition timing map storing an ignition advance value corresponding to an engine load and a rotation speed is read, and ignition is performed at the read ignition timing. The ignition is performed by outputting an ignition signal to the power transistor so that a proper ignition energy is secured. On the other hand, the operation delay time T
If D1 has elapsed, it is determined that the cam has actually been switched to the high-speed cam 22, and the routine proceeds to step 7, where the ignition timing set in advance in accordance with the state in which the high-speed cam 22 is used is set. The ignition timing is determined with reference to a map (high-speed ignition timing map), and ignition control is performed.

Similarly, when a command to switch from the high-speed cam 22 to the low-speed cam 21 is output, the learning result of the operation delay time TD2 in switching to the low-speed cam 21 is referred to, and the switching command is referred to. The switching to the low-speed ignition timing is not performed until the operation delay time TD2 elapses, and it is estimated that the switching to the low-speed cam 21 has actually been performed at the time when the time TD2 has elapsed. Switching to ignition timing is performed.

That is, even if the switching command between the low speed cam 21 and the high speed cam 22 is output, the switching is performed until the operation delay times TD1 and TD2 learned corresponding to the operating oil temperature elapse. Since the previous cam is used and the actual cam switching is performed only after the operation delay times TD1 and TD2 have elapsed, the ignition timing is switched in synchronization with the actual cam switching timing. .

Therefore, it is possible to prevent the switching of the ignition timing from being synchronized with the switching of the cam, and to prevent the occurrence of a switching shock of the ignition timing. Further, by setting the operation delay times TD1 and TD2 in accordance with the oil temperature, it is possible to cope with a change in the operation delay time due to a change in the hydraulic oil temperature, and to accurately switch the cam even when the hydraulic oil temperature is different. The ignition timing can be switched in synchronization.

On the other hand, in step 8 to step 9 or step 14 to step 15, learning update of the operation delay times TD1 and TD2 corresponding to the hydraulic oil temperature is performed. In step 8 or step 14, the intake air flow rate Qa detected by the air flow meter 105 after the cam switching command is output
The time TDR1 and the time TDR2 until the change occurs in the measurement are measured.

Next, in step 9 or step 15,
The measured times TDR1 and TDR2 and the operation delay times TD1 and TD1 stored corresponding to the current hydraulic oil temperature.
A value obtained by adding a predetermined ratio M of deviation from TD2 (current value) to the current value is used as an operation delay time T corresponding to the current hydraulic oil temperature.
D1 and TD2 are set as update data. Then, based on the update data, the data corresponding to the operating oil temperature on the map storing the operation delay times TD1 and TD2 according to the operating oil temperature is rewritten.

That is, when the cam is actually switched, the amount of air changes due to the change in the charging efficiency. Therefore, the point in time at which the change in the amount of air occurs after the output of the cam switching command is actually changed. Is performed, and the time from the cam switching command to the occurrence of the air amount change corresponds to the actual operation delay times TDR1 and TDR2.

Therefore, the operation delay times TD1 and TD2 (ignition timing switching delay times) stored corresponding to the hydraulic oil temperature are replaced with the measured actual operation delay times TD.
The operation delay time is learned by updating with R1 and TDR2 so as to be able to cope with the operation delay characteristic that fluctuates due to the variation of each engine. Therefore, in this embodiment,
Even if the correlation of the operation delay time with respect to the hydraulic oil temperature varies in each engine, the variation can be learned and the ignition timing can be switched at the timing when the cam is actually switched.

In addition, the fact that the cam is actually switched is detected by a change in the intake air amount. Since the air flow meter 105 is an indispensable sensor for the electronic control fuel injection device, it is necessary to detect the cam switching. Therefore, it is possible to easily detect cam switching without providing a dedicated sensor. During the transient operation of the engine, there is a possibility that a change in air amount unrelated to cam switching is erroneously detected as being caused by cam switching, or a change in air amount generated by cam switching cannot be detected. Therefore, during the transient operation of the engine, the learning control in the steps 8 to 9 and the steps 14 and 15 is prohibited (the learning prohibition step).
Stage). Alternatively, when the operation delay time TDR1, TDR2 having predetermined or more difference with respect to the learning value to the last time is detected, such measurement time TDR1, TDR2 may be configuration which does not update the learning map based on.

In this embodiment, the switching of the ignition timing is performed based on the operation delay times TD1 and TD2 on the learning map, and the timing at which the air amount change occurs after the switching command is separately measured. Although the above data is updated, the switching of the ignition timing is performed at the timing when the air amount change occurs, and the timing is learned according to the oil temperature in the same manner as in the above-described embodiment. The ignition timing may be switched at the learned timing only under operating conditions in which a change cannot be detected (for example, during transient operation).

In this case, even if the actual cam switching timing cannot be detected, it is possible to switch the ignition timing corresponding to the actual cam switching timing based on the learning result. However, when the ignition timing is switched with the occurrence of the air amount change as a trigger, if the air amount change cannot be detected within a predetermined time from the output of the switching command, the ignition timing is switched immediately after the predetermined time has elapsed. Preferably.

Further, in the above embodiment, the variable valve mechanism 10
Although the sensor 106 for detecting the temperature of the hydraulic oil is provided in the first embodiment, a configuration may be adopted in which the temperature of the hydraulic oil is indirectly detected based on information on the temperature of the cooling water of the engine and the elapsed time after the start.

[0054]

As described above, according to the engine ignition control apparatus of the first aspect of the present invention, the actual valve opening characteristic switching timing that is delayed with respect to the output of the valve opening characteristic switching command is detected. Since the detection timing is learned and stored for each switching direction and the ignition timing corresponding to each valve opening characteristic is switched, the switching of the ignition timing is accurately synchronized with the actual switching of the valve opening characteristic. This makes it possible to avoid the occurrence of a driving shock at the time of switching the ignition timing. In addition, learning is prohibited during transient operation of the engine.
Therefore, the actual switching timing of the valve opening characteristics
In the configuration for detecting the change in the gin intake air amount,
Avoid learning based on erroneously detected switching timing
There is an effect that can be cut.

[0055]

Further, in the device according to the second aspect of the present invention,
Since the above time is learned according to the temperature of the hydraulic oil,
Even if the hydraulic oil temperature fluctuates, the ignition timing can be switched in synchronization with the actual valve opening characteristics .

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of the present invention.

FIG. 2 is a system block diagram showing one embodiment of the present invention.

FIG. 3 is a view showing a variable valve mechanism of the embodiment.

FIG. 4 is a view showing a variable valve mechanism according to the embodiment (IV- in FIG. 3);
IV cross section).

FIG. 5 is a view showing a variable valve mechanism according to the embodiment (V- in FIG. 4);
V sectional view).

FIG. 6 is a view showing a variable valve mechanism according to the embodiment (VI- in FIG. 4);
VI cross section).

FIG. 7 is a flowchart showing valve opening characteristic switching control and ignition timing switching control of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rocker arm 2 Free cam follower 3 Main rocker shaft 7 Lever member 9 Return spring 10 Spring retainer 21 Low speed cam 22 High speed cam 31 Operating plunger 34 Hydraulic chamber 101 Variable valve mechanism 102 Control unit 103 Switching valve 104 Rotation speed sensor 105 Air flow meter 106 Oil temperature sensor

Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02D 43/00 301 F02D 43/00 301Z

Claims (2)

(57) [Claims] 1. A valve opening characteristic switching means for switching a valve opening characteristic of an engine to a plurality of preset types, and a switching for outputting a valve opening characteristic switching command to the valve opening characteristic switching means in accordance with an operating condition. An engine ignition control device comprising: a command output means; and a change in the engine intake air amount occurs after the switching command output means outputs a command to switch the valve opening characteristic.
When the valve opening characteristics are actually switched
A valve opening characteristic switching timing detection means for detecting as a ring, a timing detected by the valve opening characteristic switching timing detection means, the switching command is learned for each direction of the switched as the time from the output of updated stored The switching time learning means and the switching instruction in the switching time learning means are issued.
Learning to update the time since the force was applied to the transient operation of the engine
Learning prohibiting means for prohibiting during switching , and the switching method stored in the switching time learning means.
Ignition timing switching means for switching and setting an ignition timing set in advance for each valve opening characteristic when a time for each direction has elapsed from the switching command. Control device. 2. The system according to claim 1, wherein said valve opening characteristic switching means comprises a hydraulic oil.
The valve opening characteristics are switched by pressure.
The switching time learning means corresponds to the temperature of the hydraulic oil.
After the switching command is output, the valve
The time until the opening characteristic switches is changed for each switching direction.
The engine ignition control device according to claim 1, wherein the learning is performed .